1. Field
Embodiments according to the inventive concept relate to a method of manufacturing a phase change memory device.
2. Description of the Related Art
Data may be stored in a memory device by using a phase change material layer pattern whose resistance varies depending on whether the phase change material of the layer pattern is in an amorphous state or crystalline state. Examples of such phase change material are chalcogen compounds, e.g., germanium-antimony-tellurium (GST). In the case of chalcogen compounds, the electrical characteristics of the memory device may depend on the composition of the chalcogen compound. In addition, a desired composition of a chalcogen compound, e.g., the ratio of its elements, may be produced by appropriately controlling its deposition conditions, e.g., temperature, pressure, deposition rate, etc. However, it can be difficult to deposit a chalcogen compound having a specific composition in an opening having a high aspect ratio. For example, when depositing phase change material in an opening having a high aspect ratio, and subsequently planarizing the resulting layer of material to produce a phase change material layer pattern, the phase change material layer pattern may have a void therein or form an overhang, or nodes of the phase change material layer may not be split by the planarization process.